This error message is from HRMC and will be due to one of the following reasons:
1. Missing RTI credentials #
You have not entered credentials in the RTI reports:
- Setup > Report definitions > GB RTI FPS > Update
- Setup > Report definitions > GB RTI EPS > Update
2. Incorrect RTI credentials #
The credentials are not valid for the PAYE and Accounts office AO reference. Correct one or the other.
3. Incorrect Company PAYE and/or AO Accounts Office references #
Ensure the tax tab on the company is correct: Companies > Update > Tax tab
4. The HMRC RTI server is unable to look up the credentials #
Retry your submission at a later time – follow the steps to resend the EPS or FPS in the article Handling pay run errors (exceptions)